The present invention relates to an operator restraint bar for vehicles, primarily industrial vehicles, which are attached to the rear wall of an operator cab, and include a front cross-bar that is ahead of the abdomen of an operator when the operator is seated, and which includes impact energy absorbing components in the restraint bar.
Various operator restraint bars have been advanced in the art for self-propelled loaders and other work vehicles. The restraint bars are pivotally mounted on an operator cab structure, and generally are U-shaped or L-shaped, and are movable from a disengaged position where they permit the operator to leave the operator seat, to an operator restraining position. The restraining position may be tied in with a system that reduces the likelihood that the loader or vehicle can be operated unless the seat bar is in its proper restraining position.
A rear mounted seat bar that pivots upwardly from the restraining position to adjacent the roof of the cab is described in the above-identified U.S. Pat. No. 6,299,207. A cross bar that will restrain the operator from unintentional forward movement is rigidly connected to the pivoting arm portions that disclosure is acknowledged as prior art.
The present invention relates to a restraint bar assembly that is pivotally mounted to the rear wall of the work vehicle and has at least one side arm and a front cross bar. As shown two are formed in a generally U-shape. The side arms extend downwardly from the pivotal mounting and join horizontal arm portions when the restraint bar is in its working or restraining position. The cross bar spans or extends across the width of the seat, and is in front of a seated operator when in restraining position.
In the present invention, the cross bar is mounted to the mounting portions of the restraint bar assembly through a joint that is loaded with a spring or cushioning member to act as a energy absorbing link when the operator is moved forwardly by momentum loads or forces. Absorbing energy caused by external forces will tend to reduce loads on the restraint bar. The cross bar will be permitted to move only a limited amount for energy absorption, and thereafter will be held rigidly to function to restrain an operator from an impact.
The same spring used for energy absorption, can be used for urging the restraint bar assembly to its working position, and after the restraint bar assembly has been rotated upwardly a desired amount, the spring force will xe2x80x9cgo over centerxe2x80x9d and will act to urge the restraint bar assembly to its raised or clearance position.
The restraint bar assembly can be made with one or two springs to accomplish the energy absorption, and the spring loaded joints that operate as energy absorption sections can be located in desired positions to obtain the action wanted as well.